Fuel-feeding device



Sept. 19, 1939. M. E. BAFARO 2,173,151

FUEL-FEEDING DEVICE Filed July 26, 1937 5 Sheets-Sheet 1 Sept. 19, 1939.

M .E. BAFARO 2,173,151

FUEL-FEEDING DEVICE Filed'Jul y 26, 1937 5 Sheets-Sheet 2 Sept. 19, 1939.

M. E. BAFARO FUEL-FEEDING DEVICE Filed July 26, 195'? 5 Sheets-Sheet 4 Patented Sept. 19, 1939 UNITED STATES PATENT OFFICE- aria-.151 FUEIPFEEDING nnvrcn' Michael a. 1mm, Cicero, 111. Application July 26, 1937, Serial No. 155,801

4 Claims.

The invention relates to fuel feeding devices for internal combustion engines and for purposes of illustration is shown as employed with a retary internal combustion engine of the type wherein air is compressed and delivered into the combustion chambers at temperatures above the ignition point of the fuel, and the use of spark plugs or other ignition devices is unnecessary. A full description and disclosure of the engine is given in order that the operation of the device a? connected therewith may be better unders ood.

An object of the invention is the provision of improved means for injecting fuel and air into the combustion chambers of an engine whereby the fuel is highly atomized and perfectly disseminated through the air charge to form a turbulent combustible mixture resulting in even and complete burning during the explosion, and prevents combustion lag and inefiiclent throttlin such as isfrequently incidental to existing compression ignition motors.

Another object of the invention is the provision of an improved fuel injection pump which is simple in construction since it requires no needle valves, springs, or check valves, and utilizes the Venturi principle at its nozzle for reducing the pressure required to inject fuel into the compressed air charges as they pass from the compression chambers into the combustion chambers.

Other objects of the invention include the provision of improvements tending to simplicity, durability, efficiency, and low combustion cost.

' Many other objects and advantages of the construction herein shown and described will be obvious to thosev skilled in the art from'the disclosure herein given,

To this end my invention consists in the novel construction, arrangement, and combination of parts herein shown and described, and more particularly pointed out in the appended claims.

Referring now to the drawings wherein like reference characters indicate like or corresponding parts:

Fig. 1 is a longitudinal vertical section of the engine, taken along line l-l of Fig.2;

Fig. 2 is a horizontal section, taken along the line 2-2 of Fig. 1;

Fig. 3 is a transverse vertical section taken along the line 3-3 of Fig. 1;

Fig. 4 is a transverse vertical section, taken along the line 4-4 of Fig. 1;

Fig. 5 is a sectional view taken along the line 5-5 of Fig. 4;

' Fig. 6 is a sectional view taken along the line 6-5 of Fig. 7 illustrating the construction of bypass valves, throttle control mechanism and other details;

Fig. '1 is a transversesectional iew, taken along the line 'I-'| of R18. 1;

Fig. 8 is a transverse sectional view taken' Referring now more particularly to the drawings, the numeral l0 generally designates an oblong casing or housing, one end of which provides a pair of combustion chambers Ila and lib and the other end provides a pair of combustion chambers numbered I20 and l2b, respectively. Extending longitudinally. of the housing III is a shaft l3 having a cylindrical shaped rotor l4, positioned in and separating the chambers Ila and Nb. The other end of the shaft I3 is axially aligned with and suitably connected with a rotor l5, similar to the rotor l4, positioned in and separating the chambers l2a and 12b. The rotor is is formed on the 'end of a power shaft I6 pro-' iecting from the casing Ill in axial alignment with the shaft It. The outer ends of the rotors H and I5 are each supported by a, plurality of conical bearings H. The bearings ll for the rotor It are positioned between an outer race l8 and an inner race l9, adjacent a plate 20 suitably fastened to the casing H) by bolts 2|. A plate 22, fastened to the casing II) by bolts 23, encloses an inner race 24 and an outer race 25 for the bearings l1 supporting the outer end of the rotor IS. The two sets of bearings I1 and their respective cooperating races are so arranged as to carry the combined radial and thrust loads, to which the rotors l4 and I5 and the shafts I3 and it are subjected, with a minimum of frictons 28 radially. movable in and slideably fitting a diametric bore 21 extending through the rotors. Each bore 21 contains a compression spring 28 having its ends extending into recesses 28a provided by the adjacent ends of the pistons 26. The length of each 'piston 28 is substantially equal to the radius of the rotor in which it is mounted, and the lengths of the springs 28 are such that they permit complete retraction of the pistons in passing from one combustion chamber to the other. The resilience of the springs 28 constantly tends to move the pistons outwardly, the pressure of the springs on the pistons being supplemented by centrifugal force to maintain the pistons in close fitting contact with the peripheral bounding walls of the combustion chambers during rotation thereof. The longitudinal axes of the pistons 25 mounted on the rotor ll are positioned parallel to and extend at .right angles to the longitudinal axes of the pistons mounted on the rotor ID. The chambers I la, l lb, Ito, and i217 are preferably of the same size and the curvature, configuration and relative positions of the peripheral bounding walls, of the combustion chambers Ho and III: are identical with those shown in Fig. 3 for the chambers I20 and Ho, respectively. The curved peripheral walls of the chambers Na and Ill: and of the chambers I 2a and IN) are so spaced relative to the longitudinal axis of the rotor positioned therein that the pistons 25 comprising a pair are simultaneously moved outwardly and inwardly in equal amounts asthe rotor turns.

Air under pressure is admitted to the combustion chambers .Ila, IIb, I20, and I2!) at predetermined time intervals in a manner hereinafter more particularly described. The air is compressed by two pairs of compression pistons 29 operatively connected with the shaft I3, the pistons being respectively reciprocally movable in compression chambers 30a, 30b, 38c, and 30d, positioned alongside and in relatively close proximity to the combustion chambers. Ihe pistons 29 comprising each pair are rigidly connected by rods 3| so that they move together and at the same rate in the compression chambers. The rods 3| each terminate in a generally U-shaped member 32 fastened to the adjacent member by bolts 33. The space 34 between the connected members 32 provides a runway for a pair of blocks 35 forming a journalled bearing for the eccentric of a crank shaft 36. The inner ends of the crank shafts 36 each carry a bevelled pinion 31 in meshing engagement with a bevelled gear 38 mounted on the shaft I3. The crank shafts 36 are supported at their outer ends by a plurality of conical bearings 39, each set of bearings being positioned between an outer race 40 and an inner race 4| adjacent a cover plate 42 which is fastened to the casing III by bolts 43. The bearings 39 are adapted to carry both radial and thrust forces from the crank shafts 36.

The bevelled pinions 31 and each shaft 36 make two complete revolutions in opposite directions for each revolution-of the shaft I3 and the rotors I4 and I5. Each revolution of the crank shafts 36, by reason of their eccentric connections with the rods 3|, moves the pistons 23 from one end of the compression chambers to the other and then back to the opposite end of the chambers, thereby producing a complete compression and suction stroke of all four pistons 29. Both pairs of pistons 29 are moved simultaneously in the same direction by meshing the pinions 31 with the gear 38 so that the crank of one shaft 36 is diametrically.opposite the crank of the other shaft when the pistons are at the mid-point of their travel. During the compression stroke of one piston 29 of each pair, the other piston 29 of each pair is making a suction stroke and vice versa. In Fig. 2, one piston 29 of each pair is shown as at the end of its compression stroke and the other piston of each pair as at the end of its suction stroke. The compression chambers are each conne ted with the atmosphere by a conduit 44 which is closed by a poppet valve '45. During the suction strokes of the pistons 29, the valves 45 controlling the corresponding compression chambers open for admission of air, the valves otherwise remaining closed.

The conduits 46a, 46b, 45c, and 46d, respectively connect the compression ends of the chambers 30a, 30b, 30c, and 30d with the combustion chambers ||b, Ila, I2b, and I2a. Rotary by-pass valves "(1, 41b, 41c, and 41d, respectively closing the conduits 45, 46b, 46c, and 45d during the suction strokes of the corresponding pistons 29 and preferably remain closed until the compression strokes are completed to a point wherein the engaged by the cams 52.

air in the compression chambers is highly compressed and preferably from one-seventeenth to one-eighteenth of its normal volume. When the air has reached its maximum compression as described, the by-pass valves open to admit the compressed air into the combustion chambers, the valves opening and air being admitted while the pistons 26 are passing over the exit ends of the conduits leading to the combustion chambers,

' of bores 65 in which they are respectively mounted. A spring 66 positioned in the upper end of each bore 65 holds the by-pass valves seated to a close fit within the bores and thereby prevents escape of air around the valves.

The by-pass valves 46a and 46b are simultaneously rotated in the same direction by the oscillation of two arms 48 each having an arcuate toothed end respectively meshing with gears 49, mounted or formed on the upper ends of the valves. The arms 48 are each pivotally mounted on a pin 50 positioned intermediate their ends. A link 5| is pivotally connected with thelower ends of the arms 48 by bolts 43a, the link being reciprocally movable to oscillate the arms by the rotation of a pair of cams 52 oppositely positioned on the shaft I3. A downwardly projecting member 53, integrally formed with the link 5|, provides a cam face 54 which is successively Each resulting cam movement of the link 5| moves the toothed ends of the arms 48 to the right as observed in Fig. 6,

and thereby'simultaneously oscillates the valves 41a and 41b through ninety degrees in the same ing through the lower ends of each valve, into register with the conduits 46a and 46b respectively. A plunger 55, reciprocally movable in a bore 56, is maintained in contact with the link 5| by a compression spring 51. The spring 51 yields to permit the described cam movement of the member 52 and the link 5| and upon disengagement of the members and the cams 52. immediately returns the linkvto the position shown, thereby returning the valves 41a and 41b to their respective closed positions.

The valves 41c and 41d are oscillated, in the same manner as the valves 41a and 41b are oscillated, to open and close the air conduits 46c and 46d. For this purpose, I provideanother pair of arms 45 and a link 5| adjacent to the valves "0 and 4111, the link being actuated by contact with a pair of cams 52 oppositely positioned ,on the shaft II but in a longitudinal plane coincident with the axis of the shaft and perpendicular to the longitudinal axial plane in which the cams 52, shown in Fig. 7, are positioned. The device actuating the valves 41c and lid. is similar in all respects to that shown in Figs. 6 and 7 for actuating the valves 41a and 41b and illustration thereof is omitted as be-- ing unnecessary to a proper understanding of the invention.

The two sets of cams 52 are so positioned on the shaft that the by-pass valves Ala and 41b are opened to admit the compressed air into the combustion chambers Ila and llb as the pistons 26 on the rotor ll are moving over the ends of the conduits 46a and 46b and remain open until the pistons, shown in dotted lines, clear the conduits, and have reached the position shown in Fig. 3. This position preferably corresponds to a travel of approximately ten degrees within the combustion chambers Ila and llb, whereupon the valves "a and "b are instantaneously closed by the return movement of the link The closure of the conduits 46a and 46b occurs on the instant that the corresponding pistons 29 have completed their compression stroke, and as a result, the air-from the compression chambers 30a and 30b is driven into the combustion chambers Ho and llb back of the pistons 26 at maximum pressure. Similarly, the compressed air in the compression chambers 30c and 30d is respectively admitted into the combustion chambers I211. and llb through the conduits 46c and 46d at maximum pressure upon completion of the compression strokes of the adjacent pistons 26 positioned in said chambers.

A supply of fluid fuel is maintained in each bypass valve l'la, 41b, 41c, and 41d the fuel being delivered preferably at a pressure of approximately 20 pounds by the operation of a pump, not shown. The fuel is delivered by the pump through ducts 6| provided by the casing l0 and apertures 6la formed in the side wall ofthe valves in registry with the ducts. As best illustrated in Figs. 4 and 5, the by-pass valves each provide a longitudinal bore or'chamber 62, open v at its upper end, and in which is positioned a reciprocally movable plunger rod 63 servingboth as an injector and as a throttle for the fuel. A longitudinal bore or recess in the lower end of each rod 63 provides a chamber 64 extending 'to the periphery of the rod on one side to provide a narrow longitudinally extending slot or by-pass which is in register with the adjacent aperture 6la when the by-pass valve in which the rod is positioned is'closed to the passage of air into the combustion chamber.

The lower end of each rod 63 is shown as spaced from the bottom of the bore 62 in approximately half throttling position and is movable longitudinally in the bore in a manner hereinafter more particularly described, to inject fuel into the adjacent combustion chamber. A duct 61, extending diagonally downward from the lower endof each bore 62 to the outer periphery of the by-pass valve, terminates adjacent the discharge end of the transverse bore 60. The

discharge ends of the air conduits 46a, 46b, 56c

and 46d each provide a recess 68 as shown in Fig. 5. Rotation of the by-pass valve through 90 to bring the bores 60 into register with the air conduits also registers the lower ends of the ducts 61 with the recesses 86, and permits the fuel to be discharged from the ducts and disseminated in highly atomized condition throughout the air flowing into the combustion chambers. The by-pass valves "a and "b are rotatable independently of the rods 63 positioned therein, and when the valves are in open position,

the fuel ducts 6| are closed to admission offuel I by the outer'periphery of the valves 46a andl6b. The upper ends of the chambers 66 are also closed when the valves are in open or air and fuel discharging position, thereby preventing any backflow' of fuel when injection takes place. Upon return of the by-pass valves to closed position, the discharge endsof the ducts 6| are uncovered and permit fuel to be pumped into the chambers 64 to replace that injected into the combustion chambers. I

The rods 63 are moved inwardly to force fuel from the lower ends of the bores 62 through the ducts 61 by means of a tappet 66 carrying a roller 69 which rides over a pair of cams I0 formed onv the shaft [3. The cams are positioned on diametrically opposite sides of the rotor and approximately intermediate the longitudinal axial plane in which the cams 52 are positioned. A compression spring 'Il holds the inner ends of a pair of rocker members 12 against the outer end of the tappet 68 and yields to permit upward movement of the tappet and corresponding rotation of the rocker members. The rocker members 12 are journalled at one end in brackets I3 and at the other end in the casing It as best shown in Figs. 1, 6, and 8.

The upper end of the rod-63, positioned in the by-pass valve "a, is integrally formed with a transversely extending bar 14 and the upper end of the rod 63, positioned in the by-pass valve,

41b, is integrally formed with a similar bar'l5. The bars 14 and 16 have a close fitting tongue and groove connection, as shown in Fig. 4, whereby the bars and the rods 63 connected therewith are moved together vertically by the rocking of the members 12. The members 12 are respectively operatively connected with the bars 14 and 16 by pins Tl, projecting through elongated slots 18 provided in upwardly projecting flanges 18 formed on the bars. The pins 11 are each carried by a rack 80, respectively longitudinally movable in the members 12 in a manner and for a purpose hereinafter described. Rocking of the members 12 by the tappet 66 as above described oscillates the pins 11 in an arcuate path. The engagement of the oscillating pins 11 with the bars H and 16 results in correspond- 1 ing vertical movement of the bars and the rods 63. Upward movement of the tappet 66 is so timed as to rock the members 12 to force'the rods 63 downwardly at the instant the by-pas. valves "a and 41b are moved to open the condiiits 46a and 46b to the delivery of charges of air and fuel into the combustion chambers Ha and llb, respectively. Return of the tappet 68 downwardly to its original position, by the action of the spring II when the roller 66 has passed over a cam 10, moves the bars 14 and I5 and the rods 63 back to their respective positions shown in Figs. 4 and 5 wherein the valves "a and l'lb' are closed. Since the tappet 68 is moved upwardly twice for each revolution of the rotor ll,

two charges of air and fuel are delivered into the combustion chambers Ila and llb during each revolution of the rotor. The injection devices for delivering fuel into the combustion chambers Ma and lib, provided by the rotor 15, are identical in construction with the devices described for delivery of fuel and air into the chambers Ila and I lb and their operation is similar, other than that the delivery into the latter chambers occurs at timed intervals exactly intermediate the delivery into the former.

The bars II and I6 and the rods 63 are shown in Figs. 4 and 7 as at the end of their upward strokes resulting from rocking of the members 12. The quantity of fuel delivered into the combustion chambers with each air delivery obvi-' ously depends upon the length of the strokes of the rods 03 in the bores 62 of the by-pass valves.

The length of such strokes and the position of the bars I4 and I5 and the rods 63 when the upward strokes are completed depend upon the position of the pins II in the inclined portions of the slots 18. The lengthvof the arcs through which the pins 11 are oscillated depends upon the radial distance of the pins from the axes of oscillation of the members I2, since the racks 80 carrying the pins are rocked with the members. For any given position of the pins 11 in the inclined portion of the slots 18 there is a corresponding length of stroke of the rods 63 and a uniform injection of fuel through the ducts 61 by each stroke.

The position of the pins H in the slots I8 is shifted as hereinafter described to throttle the fuel. If the amount of fuel delivered by each stroke of the rods 63 is to be increased, this is accomplished by moving the pins 11 outwardly since the radial distance of the pins from the axes of rotation of the members 12 and the length of the are through which the pins are oscillated are thereby increased. If the amount of fuel delivered with each charge is to be diminished, this is accomplished by movement of the pins I1 inwardly in the inclined portions of the slots 18, since the radius and the length of the arc of oscillation of the pins are thereby shortened. The described outward and inward movements of the pins TI, to accomplish throttling of the fuel, are along lines perpendicular to the axes of the rods 6.3, and since the slots are inclined as shown, the outward movement of the pins raises the bars 14 and I5, and the rods 63 respectively carried thereby. Inward movement of the pins 11 in the inclined portion of the slots 18 moves the bars 14 and I5 and the rods 63 downwardly so that the lower ends of the rods are closer to the bottom of the bores 62- in the by-pass valves. The position of the rods 68 in the by-pass valves for any setting of the pins 11 is such that the longitudinal stroke of the rods is accomplished without striking the bottom of the bores 62 in the by-pass valve.

The upper ends of the slots IO terminate in arcuate portions having as their respective centers the axes of rotation of the rocker members 12, and when the pins II are positioned in the arcuate portions, their oscillation by the rocker members does not produce any vertical movement of the bars I4 and I! and the rods It carried thereby, the rods remaining stationary in their most advanced position and as a result no fuel is delivered into the combustion chambers with the air.

The described shifting of the position of the pins 11 in the slots I8 to throttle the fuel by varying the length of strokes and the position of the rods 68 in the by-pass valves, is accomplished by outward and inward movement of the racks 80 carrying the pins. The racks ll are respectively actuated by pinions OI machined on shafts l2 journalled in the rocker members 12. The pinions iii are positioned in bores I! of generally cylindrical shape and providing openings through which the pinions project adjacent the racks II. with such projecting portions in mesh with the racks.

The projecting ends of the two shafts 82 provide pinions 84 respectively in meshing engagement with one of a pair of vertically movable racks 85. The racks 85 are rigidly connected r withoneend ofabar asbestshowninllgs.

1 and 8. A throttling device, operable to control the movement of the rods 3 in the by-pass valves 41c and "d, similar in construction and operation to the throttling device described for the rods 63 in valves "a and "b, has a pair of racks 85 rigidly connected to the other end of the bar 86. The bar 86 is movable vertically, by a longitudinally movable manually actuated throttle rod 81, to simultaneously actuate both pairs of racks 85. The rod 01 projects through the top of the casing Ill and downward movement thereof simultaneously actuates the racks 85 to rotate the shafts 82 to move the racks 80, and the pins 11 outwardly in the slots 18 in equal amounts. As a result of this outward movement, the length of the strokesof all the rods 63 are similarly and equally increased and the delivery of fuel to each combustion chamber is equally and evenly throttled. Upward movement of the throttling rod 81 likewise simultaneously moves the racks 85 to actuate the racks I and move the pins Il inwardly in the slots ll whereby the length of the strokes of all the rods 63 is decreased,- and the amount of fuel injected. into the combustion chambers is correspondingly diminished, such injection ceasing entirely when the pins ll are in the arcuate portions of the slots 18.

From the foregoing description, it is obvious that all four ofthe pins 11 are'moved to occupy similar positions in the slots 18 by manipulation of the rod 81. The full line intermediate position of the pins 11, shown in Fig. 4, corresponds to partial throttling of the injection devices and Fig. illustrates the retracted position of the plunger rod 88 in the valve 41a. corresponding to the illustrated full line position of the pin, it being understood that Fig. 5 also illustrates the fully retracted position of the rods 83 positioned in the valves "b, He, and 41d respectively for the full line position of the pins in Fig. 4. In the illustrated full line position of the pins 11 in the slots 18 their oscillation by the rocker members I2 lowers the rods 63 from the position shown as hitherto described and then returns the rods to the position shown in Fig. 5. 0bviously, the amount of fueldelivered through the ducts 81 by the downward movement of the rods It depends upon the length of their strokes and since this varies with the position of the pins 11, a maximum amount of fuel is delivered when the pins 11 are in the dotted line positions near the outer end of the slots and no fuel is delivered when the pins are in the dotted line position at the upper end of the slots, since in the latter position, the 63 are stationary with their inner ends in close proximity to the bottom walls of the bores or chambers II in the valves. Any position of the pins 11 intermediate the dotted line positions will correspondingly shift the position of the rods 63 in the bores or chambers 62 and will also vary the length of the strokes of the rods and the amount of fuel delivered by their reciprocation.

Thus, it will be seen that I have provided efilcient and novel throttling and injection devices which are simple, durable, and satisfactory for their intended purpose.

Having thus described my invention, it is obvious that various immaterial modifications may be made in the same without departing from the spirit of my invention; hence I do not wish to be understood as limiting myself to the exact form, construction, arrangement and combination of parts herein shown and described or uses mentioned.

What I claim as new and desire to secure by Letters Patent is:

1. A fuel injector pump of the kind described comprising a casing providing a bore. said casing also providing a fuel inlet conduit and a fuel discharge conduit each communicating with said bore, a barrel closely fitting said bore and having its inner end closed, means for imparting angular oscillation to said barrel, a plunger rod fitting snugly within said barrel, means for reciprocating the rod longitudinally within the barrel whereby the space between the inner end of the rod and the inner end of the barrel provides a pump chamber, the side wall of the barrel providing a port which communicates with said fuel inlet conduit when the barrel is at one end of its oscillatory path, the closed end of said barrel providing a relief duct connected with said chamber and which connects with said fuel discharge conduit when the barrel is at the other end of its oscillatory path, said barrel and plunger rod being operable in timed relation whereby the rod, in approaching the end of its return stroke, uncovers said port/while it is in communication with the fuel inlet conduit and the rod, during its initial pump stroke, covers said port simultaneously with movement of the barrel to a position wherein the relief Iduct communicates with said fuel discharge conduit, said barrel being moved to close the relief duct upon complet on of the pump stroke of said rod.

2.. A fuel injector pump of the kind described comprising a casing providing a bore, said casing also providing a fuel inlet conduit and a fuel outlet' conduit each communicating with said bore, a barrel closely fitting said bore and having its inner and closed, means for imparting angular oscillation to said barrel, a plunger rod fitting snugly within said barrel, means for reciprocating the rod longitudinally within the barrel whereby the space between the inner ends of the rod and the barrel provides a pump chamber, the side wall of the barrel providing a port which communicates with said fuel inlet conduit when the barrel is at one end of its oscillatory path, the closed end of said barrel providing a relief duct connected with said chamber and which connects with said fuel outlet conduit when the barrel is at the other end of its oscillatory path, said barrel and rod being operable in timed relation whereby the rod, in approaching the end of its return stroke, uncovers said port while it is in'communication with the fuel inlet conduit and.

' the rod, during its initial pump stroke, covers said port simultaneously with the movement of the barrel to a position wherein the relief duct communicates with said fuel outlet conduit, said barrel being moved to close the relief duct upon completion of the pump stroke ofv said rod, and means operable to control said rod reciprocating means to vary the length of strokes of the rod and thereby to regulate the amount of fuel delivered through said relief duct into the outlet conduit by each pump stroke of the rod.

3. A fuel injector pump of the kind described comprising a casing providing a bore, said casing also providing a' fuel inlet conduit and a fuel discharge conduit each communicating with said bore, a barrel closely fitting said bore and having its inner and closed, means for imparting angular oscillation to said barrel, a plunger rod fitting snugly within said barrel, means for reciprocating the plunger rod longitudinally within the barrel whereby the space between the inner ends of the rod and barrel provides a pump chamber, the side wall of the barrel providing a port which communicates with said fuel inlet conduit when the barrel is at one end of its oscillatory path, the closed end of said barrel providing a relief duct connected with said chamber and which connects with said fuel discharge conduit when the barrel is at the other end of its oscillatory path, said rod extending inwardly beyond said barrel port and providing a recess or bore extending outwardly beyond said fuel inlet duct when the hood is at the beginning of its pump stroke, said recess terminating in a longitudinally elongated laterally extending oriflce positioned to receive fuel from the inlet conduit when said barrel port is in communication with said conduit, said barrel and plunger rod being operable in timed relation whereby the rod, in approaching the end of its return stroke moves the orifice to open said port while it is in communication, with the fuel inlet conduit and the rod during its initial pump stroke covers said port simultaneously with movement of the barrel to a position wherein the relief duct communicates with 'said fuel discharge conduit, said barrel being moved to close the relief duct upon completion of the pump stroke of said rod.

4. A fuel injector pump of the kind described comprising a casing providing a bore, said casing also providing a fuel inlet conduit and a fuel discharge conduit each communicating with said bore, a barrel closely fitting said bore and having its inner end closed, means for imparting angular oscillation to said ..barrel, a plunger rod fitting snugly within said barrel, means for reciprocating the plunger rod longitudinally within the barrel whereby the space between the inner ends of the rod and the barrel provides a pump chamber, the side wall of the barrel providing a port which communicates with said fuel inlet conduit when the barrel is at one end of its oscillatory path, the closed end of said barrel providing a relief duct connected with said chamber and which connects with said fuel discharge conduit when the barrel is at the other end of its oscillatory. path, said rod extending inwardly beyond said barrel port and providing a recess or bore extending outwardly beyond said fuel inlet duct when the rod is at the beginning of its pump stroke, said recess, terminating in a longitudinally elongated laterally extending orifice positioned to receive fuel from the inlet conduit when said port is in communication with said conduit, said barrel and plunger rod being operable in timed relation whereby the rod, in approaching the end of its return stroke moves the orifice to open said port while it is in communication with the fuel inlet conduit and the rod during its initial pumpstroke covers said port simultaneously with movement of the barrel to a position wherein the relief duct communicates with said fuel dlsmcnsnn E. BAFARO. 

